In The Field: June 21, 2007
Based on samples arriving to the lab this week, Pythium blight, brown patch (caused by Rhizoctonia zeae), and anthracnose are active throughout the region. These diseases can cause severe damage in a relatively short period of time, so preventive applications of an effective fungicide are warranted. Caution should be used when treating for R. zeae as some traditional brown patch fungicides (e.g., thiophanate-methyl) may be ineffective.
Although less widespread than in recent years, anthracnose basal rot has caused significiant damage to select golf courses in the region. Fungicide trials over the last two years at courses in Greenwich, CT have revealed considerable differences in fungicide efficacy. Results of these two studies suggest that selecting an effective fungicide for your course will take some local knowledge. While the QoI's tested in 2006 provided little to no control, they provided the greatest level of suppression in the 2007 study. The two studies were conducted on golf courses only a couple of miles apart.
Finally, remember to assist us in our dollar spot research by sending in dollar spot samples from putting greens and fairways. If dollar spot is not appearing on your course, go the extra step and place a small board (6" x 6") on the back of your putting green or fairway prior to your next spray. Results of this study will assist in determing the level and type of fungicide resistance prevalent in New England.
In The Field: June 1, 2007
Disease-related problems have been few due to the lack of rain that we have received throughout the region. In some regions, dollar spot has started to appear. Early season applications of fungicides for dollar spot control, however, still appear to be holding up well.
The few disease issues that we have seen throughout the region include anthracnose basal rot, dollar spot, brown ring patch, and continued cases of fairy ring. We are several weeks away from seeing outbreaks of brown patch and other summer diseases.
Although diseases have been kept to a minimum, weeds are hitting their stride. Crabgrass has germinated throughout the region and in many cases have grown too large for early post-emergence control. Yellow nutsedge has also been seen in the Southwestern portion of Connecticut and probably is starting to germinate in regions farther north as well.
SEND YOUR SAMPLES to Support Dollar Spot Research
By John Kaminski
Funded by the New England Regional Turfgrass Foundation, Syngenta Crop Protection and the United States Golf Association, researchers at the University of Connecticut are investigating various aspects of managing dollar spot. Research will focus on improving fungicide efficacy through the proper selection of nozzle-types (see the June 2006 issue of GCM for more information) as well as through unconventional application timings.
In addition to developing improved management strategies, researchers will seek to determine the importance and scope of pathogen resistance to fungicides commonly used to control dollar spot. To participate in this component of the project, please send dollar spot samples from fairways and/or greens to the University of Connecticut (dollar spot samples submitted during the study will not be charged a diagnostic fee).
UCONN Turfgrass Disease Diagnostic Center
c/o John Kaminski
University of Connecticut
1376 Storrs Road, Unit 4067
Storrs, CT 06269
For more information on this research project or disease diagnostic services at UConn, please contact John Kaminski (860.486.0162 or email@example.com
In The Field: May 23, 2007
Dollar spot is finally active in several regions across the state and will probably be present throughout the Northeast soon. For those of you who applied an early season fungicide application for dollar spot, you should have a slight delay in symptom development and more time to respond with a follow up application once symptoms do appear. For those who chose not to make an early season application, now is the time for preventive treatments. Waiting for extensive symptoms to develop may lead to more difficult control and higher fungicide use rates.
In discussions with superintendents across the state, aerification appears to be a high priority. Recovery during the next week or two should be quick due to the excellent growing conditions. If you can get away with it, continue to punch holes in putting surfaces with needle or pencil tines or even with star or bayonet tines until the heat of the summer. The benefits of the increased air exchange and increased water infiltration will be seen well into the summer months.
The diagnostic center continues to receive samples of brown ring patch and fairy ring, but have also observed several cases of mechanical damage from mowing wet greens and also chemical burn. Most cases of chemical burn have been attributed to the concentrated dripping of wetting agent tablets during applicaiton. Although symptoms may be several weeks off, preventive applications for the control of summer patch are here. To fine-tune applications to your specific site, experiments by Dr. Vargas at Michigan State suggest applying preventive summer patch control when soil temperatures at a two inch depth at 2:00PM reach 65F for several consecutive days.
In The Field: May 1, 2007
Weather has finally warmed up and with the temperatures comes the disease activity, Poa seedhead development, and germination of those summer annual weeds. Most turfgrass managers across the state have treated for Poa seedheads and the application of preemergents for crabgrass control is in full swing.
Temperatures around the region have been and look too be great for growing grass. Temperatures throughout Connecticut are predicted to be in the 60's with a chance of rain on Wednesday. The 7-day outlook for several towns are as follows:
* Danbury, CT: Low 39, High 69
* Greenwich, CT: Low of 43, High of 71
* Hartford, CT: Low of 41, High of 69
* Norwich, CT: Low 38, High 69
* Old Saybrook, CT: Low 38, High 66
* Putnam, CT: Low 38, High 67
* Torrington, CT: Low 37, High 67
Based on site-visits and samples received in the diagnostic lab, several diseases are active in the field. Diseases to watch for include anthracnose basal rot, brown ring patch (BRP; aka Waitea Patch), and fairy ring. Reports from the mid-Atlantic indicate that brown ring patch is causing major problems on many golf courses in the Philadelphia area. We have only seen a few cases of BRP this year, however, warmer temperatures are likely to increase the incidence of this poorly understood disease. We appear to be moving towards warmer temperatures, but turfgrass managers should be on the watch for late outbreaks of Microdochium patch (aka, pink snow mold).